I am an engineering student and I was wondering if someone may be able to help me find some information about the flash synchronizer shown in the picture I attached. I've done a little research on it so far, but I thought, what better way to gain more information than to ask the experts. I'm of the understanding that a man named Irving Jacobson invented it in 1939. If you can give me any related information, trivial, technical, or otherwise, it would be greatly appreciated. The patent number I have been given is 2161355, but when I searched for that number it came up with something that did not look like the item I'm researching, although it was very closely related and of the same time period. Any help would be great! Like I said, any information that is even remotely related to this item would be helpful. Also, please send me references or links with any info you may provide if possible. Thanks!

It's magnetic solenoid shutter tripper used to synchronize the shutter with the flash bulbs. If you seach this site you should find some details on it's use. The one pictured was made by Heiland Research, in Denver (Littleton), CO. 1939 was the infancy stage of flash bulbs that were consistent in operation enough to be synhronized.
Prior bulbs were very inconsistent in the time to peak output. They were used for open flash only. News photographers of the day were largely resonsible for the advent of flash synchronization. There were many devices on the market at the time. A company did make Jacobson flash guns and synchronizers. I really don't think the one pictured was related, but anything is possible. An excellent reference book published in 1939 by Willard D. Morgan of Morgan & Lester Publishing Co. -- Synchoflash Photography is an interesting read. Scarce book. Very hard to find. As an aside, the solenoid pictured is a later model. The early Heilands were round and looked very much like the Graflex solenoids. I hope this helps in your search._________________Glenn

According to a "history of..." pamphlet, Heiland Research of Denver, Col. was a mining equipment company on the brink of bankruptcy when one of their managers showed a boss what he'd been working on at home. It was a flash synchronizer and his name was Sidney O. Lindall (Lindahl?).

The Boss took the idea and ran with it, and it saved the company. The early battery cases were labeled 'SOL' Heiland flash units, with the double entdre being SOL was both the name of the sun god and Sidney's initials.

Irving Jacobson was an LA engineer that helped a friend photographer and in doing so, invented the Jacobson synchronizer. He was about to launch a new and improved version when the President of Graflex made him an offer he couldn't refuse, and headed up the Western Division of Graflex.

Sometime later on, somebody decided that the HR synchronizer infringed on Irving's patent and a deal was struck. Some HR solenoids have Irv's patent, but he never set foot in Denver, and as far as I know Irving never met Sid.

One of the "novel and useful" ideas Irving had was to use a hollow iron core which gave a lot of torque at the beginning where you needed it. previous designs used solid core coils, much like door bell buzzers, that had tremendous power at the end of the cycle, but hardly any at the beginning when you needed to overcome the shutter trip resistance.

He also hit upon the idea of a little play in the linkage to give the solenoid some unloaded inertia.

Exactly what part of HR's solenoid infringed on Irv's patent is unknown._________________"In order to invent, you need a good imagination and a lot of junk" Thomas Edison

"SOL" (or "S.O.L.") also means "s**t out of luck," and was a common slang vulgarism in the '20s and '30s. Louis Armstrong and his Hot Seven recorded a piece titled "S.O.L. Blues" in 1927. I'd be willing to bet that this usage wasn't lost on at least some of the photogs of the day who were in the know.

Excellent responses so far. This is exactly the type of information I was looking for and it seems to add up to what research I've done myself so far, plus a lot of new info. Thanks a bunch for the knowledge and references. Keep it coming if you've got anything else. Looks like I came to the right place.

Some further info picked up over time....hope I am not repeating what may have been posted on this topic before.

For a while Heiland Research Corp licensed the patented from S.O.L, but after awhile bought it outright, which is why early Heilands had the SOL logo, which shouldn't be confused with KING SOL which was the predicessor of Paramount cords.

One time at the Paramount site I clicked on http://www.paramountcords.com/
and then on: Profile - company history and GUESS WHAT?! Read about it being founded by the man who was King Sol !
I wrote Gary at Paramount Cords and had this reply which further filled me in on things......not as much as I would have expected from a grandson of the founder of King Sol...... and not much about Heiland, which was a disappointment. However .....here is my message to him and his reply....

>>>>"Just idly reading your company history and was astonished to learn it all started from the King Sol company!
Would you mind expanding on this a bit? I know from the appearance of KIng Sol and Heiland flash guns that there must be a connection. I surmize that maybe someone from King Sol left the company and started up a competing brand and called their company Heiland. Am I correct, or what is the connection.....I am sure there must be one.
Love to hear about this if you have a moment."<<<<

>>>>>"Len: Thanks for your interest in the King Sol history. It's nice to know somebody reads that page. Why your interest in King Sol?
Yes, there was a connection there between Heiland and King Sol. I have some King Sol stuff with both Heiland and King Sol logos on them. I also have some sync cord molds with the Highland logo on them. (Len comments: WOW wish I had the money to order up Gross of each and sell them on eBay!) I don't know the whole history, but I do know that Herman Fish (my Grandfather) did have a partner. I think his name was Robbins or Roberts......I heard he wasn't a good guy.

After King Sol, Herman Fish went out on his own and concentrated on plastics. When plastics was in its infancy, he had the idea to make plastic utensils. Everyone discouraged him from making it so he didn't. They laughed and said: " why would anyone want to buy plastic forks and spoons and knoves". To bad he didn't patent the idea. After King Sol, he opened a factory in Hawthorne NY which did injection molding of boxes, jars and lids.

In the later years of his life he was sort of semi-retired, and was into everything from photography to aeronautics. When I was about 7 years old (1958), I watched him make parts for experimental rockets out of fibreglass type materials (along with sync cords) in his home in Putnam, NY. He also made strobe lights for parachuters etc. He died in his sleep in 1982 with a toothpick still in his mouth.

I have a nice sync retrofit for a twin lens camera made by King Sol, also a King Sol flashgun with 3 reflectors. I collect the King Sol stuff.

Best regards Gary, Paramount Cords.

The KING SOL came out after the war and was a direct and unlicensed copy of the SOL flash. But by this time HR was now the HR division of Honeywell and Sidney wasn't getting anywhere with the Honeywell brass about going after King Sol. He finally left HR and opened a camera store. After electronic flash was on the upswing, Honeywell did get King Sol to cease and desist.
I think that's why the details of Herman Fish and the King Sol company are so sketchy with the gg grandson. there's a lot of skeletons in that closet and Herman didn't talk much about it.
(This last commen by Les some time ago).